When it was first commissioned in 1926, US 87 went only as far south as Rawlins:

c. 1927, Rand McNally

This photo was looking south on 3rd Street (Business US 287) where it intersects Spruce Street (US 30):

Sanderson, Mar. 2001

(detail)

Today US 30 and Business 287 are overlapped straight ahead for a few blocks, and then left on Cedar Street. But back when US 87 served Rawlins, the configuration was a little different: US 30 used 5th Street (not 3rd) to make the jog between Spruce and Cedar. That is only two blocks to the right, so presumably US 87 traffic wanting westbound US 30 would have been directed to turn right at that intersection. But officially US 87 continued ahead three blocks from the scene shown above, ending at Cedar:

In 1936, that segment of US 87 became US 287, and the US 87 designation was changed to its present corridor through Cheyenne.

Originally the north end of US 87 was at Piegan, on the Canada border (where US 89 ends now). In 1934, US 89 was extended north and joined US 87 at Armington MT (southeast of Great Falls). The two routes were co-signed into that city, where US 87 then ended, with US 89 taking over its former route up to Piegan (photos and more info on the Great Falls page.

​The next year, the south end of US 87 was extended all the way down to its present terminus in Port Lavaca:

c. 1936, TXDoT

This shot shows the last southbound marker on Main Street, although drivers are actually heading northeast here:

Brooks, July 2010

The southernmost point on US 87 is about a half-mile behind the camera. ​ A few blocks ahead, there was no "End" sign, only a junction sign:

Karners, Jan. 2015

US 87 ends at the stop sign just ahead; beyond that lies Lavaca Bay and Point Comfort. The cross road is Commerce Street, or TX hwy. 238:

Wiley, 2000

Karners, Jan. 2015

Formerly there was a sign pointing left that said "To TX 35", but that was no longer there as of 2010; signage now indicates that TX 238 runs both ways along Commerce. The right-hand side of that "goalpost" is used to sign the south beginning of US 87 for northbound TX 238 traffic; that perspective is shown here:

Brooks, July 2010

The sign below read "Where Highway 87 Ends the Party Begin" [sic], proving that sometimes even non-road-geeks notice things like highway endpoints. The beginning as seen from the opposite direction is signed thus:

Wiley, 2000

That assembly has since been replaced, but it is essentially the same. That is posted just after the intersection with Main, heading southeast on Commerce. Straight ahead is also part of Lavaca Bay; the Gulf of Mexico itself is 20 or 30 miles in that direction. That sign is also shown at far left in this photo:

Brooks, July 2010

That shows an overview of the intersection where US 87 begins, straight ahead on Main. At far right is a "Lavaca" theater sign; that is where the first northbound confirming marker is posted:

Wiley, 2000

Brooks, July 2010

From there, US 87 takes travelers further southwest for about a half-mile; then west for about four more; and then finally northwest towards Victoria... and ultimately to Montana.

It was about 1945 when the US 87 designation was extended northeastward to Havre. Southwest of town, US 87 initially followed Old Post Road / 11th Street to 1st Avenue; north one block; east on 10th Street to 3rd Avenue; then north to end at US 2, which ran along 2nd Street on the west side of town, not 1st Street (as it does today):

c. 1951, MT DoT

This interactive image is looking north on 3rd Av, approaching 2nd St. US 87 ended here; straight ahead was eastbound US 2, while westbound was to the left:

​In 1951 US 87 was changed to its current alignment, which junctions with US 2 a few miles west of town:

Millsap, 2000

That was heading north on US 87; ahead in the distance, down at the bottom of the Milk River valley, the "T" intersection where the highway ends is visible. These shots were taken from that junction:

Millsap, 2000

Millsap, 2000

Downtown Havre is about three miles east (to the right). Here we are looking west on US 2:

Elbert, July 2004

The north beginning of US 87 is to the left. Next are some views from the opposite direction:

Elbert, July 2004

Elbert, July 2004

The control city to the right is Great Falls. Travelers who take that turn will soon see the first southbound confirming marker: